Milrinone improves oxygenation in neonates with severe persistent pulmonary hypertension of the newborn.

BACKGROUND Many neonates with severe persistent pulmonary hypertension of the newborn (PPHN) are nonresponders to inhaled nitric oxide (iNO). Milrinone is a promising adjunctive therapy because of its pulmonary vasodilator properties and cardiotropic effects. DESIGN Case series of neonates with severe PPHN (defined as oxygenation index [OI] >20, failure of iNO therapy, and echocardiographic confirmation of PPHN). SETTING Tertiary neonatal intensive care unit. SUBJECTS Full-term (> or =37 weeks) neonates with severe PPHN who received intravenous milrinone. MEASUREMENTS The primary end point was the effect of intravenous milrinone on OI and hemodynamic stability over a 72-hour study period. Secondary end points examined included duration of iNO and degree of cardiorespiratory support. RESULTS Nine neonates at a mean gestation of 39.25 +/- 2.76 weeks, birth weight of 3668 +/- 649.1 g, and baseline OI of 28.1 +/- 5.9 received milrinone treatment after a poor initial response to iNO treatment. Intravenous milrinone was commenced at a median age of 21 hours (range, 18-49 hours), and patients were treated for median of 70 hours (range, 23-136). Oxygenation index was significantly reduced after milrinone treatment, particularly in the immediate 24 hours of treatment (8.0 +/- 6.6, P < .001). There was a significant improvement in heart rate (179 +/- 15.2 vs 149.6 +/- 22.4, P < .001) over the same period. Infants who received milrinone did not develop systemic hypotension; in fact, there was a nonsignificant trend toward improved blood pressure. CONCLUSIONS Intravenous milrinone produces early improvements in oxygenation without compromising systemic blood pressure.